Update, 8:06 p.m: The lower deck of the Western Hills Viaduct has re-opened following repair work to remove loose exterior concrete from the underside of the upper deck.

Original reporting: Public safety officials shut down the lower deck of the Western Hills Viaduct Tuesday afternoon due to falling debris.

A truck's windshield was damaged but no injuries were reported at the bridge. The top deck is a major thoroughfare that carries 55,000 vehicles per day. Both decks span the Mill Creek Valley and CSX Railroad Yard.

The upper deck remains open.

Buy Photo

Authorities respond and clean up fallen debris from the lower deck of the Western Hills Viaduct, Tuesday, July 18, 2017, in Cincinnati. (Photo: The Enquirer/Kareem Elgazzar)

Deterioration of the bridge has been a concern for years. Its last major rehab was in 1977.

It's not the first time debris has fallen from the top deck to the bottom, said Hamilton County Engineer Ted Hubbard.

"We're not making light of it," Hubbard said Tuesday, who added that a bridge engineer was on the way to inspect the damage as of 3:45 p.m.

It was unclear when the lower deck, which connects to Spring Grove Avenue, will reopen.

Buy Photo

Authorities respond and clean up fallen debris from the lower deck of the Western Hills Viaduct, Tuesday, July 18, 2017, in Cincinnati. (Photo: The Enquirer/Kareem Elgazzar)

"We are very, very serious about pushing forward to get the western hill viaduct project done," Hubbard said.

The good news is the city and county signed an agreement earlier this year on how to pay for maintenance, Hubbard said. Hubbard's office is in the midst of selecting the company that will get the detailed designs done.

Buy Photo

Authorities respond and clean up fallen debris from the lower deck of the Western Hills Viaduct, Tuesday, July 18, 2017, in Cincinnati. (Photo: The Enquirer/Kareem Elgazzar)